"Fluid in your ears"

Most people are familiar with the diagnosis by doctors of "fluid in the ears". It is characterized by a "dullness" of hearing or a "stuffed-up" sensation in the ears, and may be accompanied by ear-ache. This type of "fluid in the ears" is not the normal state, and represents a disease of the middle ear which should be treated by a physician. Our group does not study this type of "fluid in the ears". The following page is intended to help clarify what is meant by the widely used description of "fluid in the ears" with regard to middle ear disease.

Anatomy of the Ear

This figure shows a schematic of a section through the head, showing the main components of the ear. The ear canal, as far down as the ear drum, makes up the outer ear. The middle ear is the cavity behind the ear drum which contains the middle ear bones. The inner ear includes the blue coiled structure, the cochlea, which is the subject of our research.

Schematic of the normal ear

This figure shows a more schematized version of the above illustration. The color white indicates the air-filled spaces. The ear canal is air-filled, as is the middle ear space. The air in the middle ear space is important to allow the ear drum and middle ear bones to be vibrated by sounds collected by the ear canal. The middle ear space is connected to the back of the throat by the eustachian tube. The eustachian tube is normally closed, but opens when we swallow. If we go up or down hills, or ride in a plane, air pressure differences between the middle ear and the ear canal can "stiffen" the ear drum so that it collects sound vibrations less efficiently. This generates a "plugged up" sensation in the ears. Swallowing opens the eustachian tube and allows the middle ear pressure to be equalized with the external air pressure, thereby improving hearing sensitivity.

Fluid in the ear

In a number of diseases, fluids, shown here colored blue, may accumulate in the middle ear space. This affects hearing, by reducing the mobility of the ear drum, so that sounds are not collected as efficiently. The fluid may also affect the function of the inner ear, by disturbing the normal chemical composition of the inner ear fluids. This type of fluid in the ear is thus an abnormal state, which should be treated by a physician. Our research does not study this type of fluid in the ear. Rather, we study the fluid within the inner ear, which is shown orange in the picture above.